The Seven Troughs Mining District is a historic gold-silver mining area located in the Seven Troughs Range in Pershing County, northwestern Nevada, approximately 35-50 miles northwest of Lovelock and northeast of Reno. It represents a classic early 20th-century Nevada boom-and-bust mining camp, with activity peaking from about 1907 to around 1918-1920, followed by decline and intermittent small-scale operations into the mid-20th century.
Geology
The district is situated in the northwestern Basin and Range province. Mineralization occurs primarily as epithermal vein deposits in Tertiary volcanic host rocks, with gold and silver in quartz veins. The deposits are associated with hydrothermal alteration, including an early pervasive propylitic event (altering rocks to assemblages like chlorite, epidote, and calcite) and later events. Veins are structurally controlled, often along faults or fractures in the volcanic sequences. The Kindergarten vein was particularly notable for high-grade pockets. The area features significant mine dumps and tailings, with historical production focused on rich bonanza-style ore shoots. Modern assessments (e.g., from NBMG and USGS-related maps) highlight potential geothermal ties due to the range’s structure, but primary economic interest remains precious metals.
History and Development
Gold was first discovered in 1905 in Seven Troughs Canyon (named for seven watering troughs built in 1894 by sheepman Frank M. Ward to water livestock). A Lovelock blacksmith named Joe Therien (or similar accounts credit prospectors tracing float) found gold-silver ore while camping. Assays from early finds, particularly on the Fairview claims, revealed exceptionally rich ore—some pockets reportedly running as high as $100,000 per ton in gold and silver values (at early 1900s prices, equivalent to immense wealth today).
News spread rapidly, drawing prospectors from booming areas like Goldfield and Tonopah. The district formalized around 1906-1907, with hundreds of claims staked. Peak activity occurred in 1907-1908, with up to 5,000 people in the area at times. Four main towns sprang up:
- Seven Troughs (primary and most stable town near the best mines; post office 1907-1918).
- Vernon (initial hub, established ~1905-1906).
- Mazuma (at the canyon mouth; devastated by a catastrophic flash flood in 1912 that killed about 20 people and destroyed much of the town).
- Farrell (smaller camp).
Additional settlements included Tunnel Camp (or New Seven Troughs), developed around a failed 2.5-mile drainage tunnel project in the 1920s-1930s by the Nevada State Gold Mines Company.
A devastating 1912 flood in Seven Troughs Canyon wiped out Mazuma and parts of the infrastructure, contributing to decline. Water in deep workings (flooding mines like Coalition, Seven Troughs, and Mazuma Hills) forced closures despite efforts to drain them. By 1918-1920, major activity ceased, though small operations continued sporadically into the 1950s. The district never connected by railroad despite 1907 plans.
Significant Mines
The district’s production centered on high-grade veins, especially the Kindergarten vein (famous for bonanza ore). Key mines included:
- Fairview (initial rich discovery; part of Seven Troughs Mining Company).
- Silver Coalition (or Coalition).
- Cleghorn.
- Dixie Queen.
- Mazuma Hills.
- Kindergarten (group of leases with spectacular high-grade ore).
- Others like Seven Troughs and various smaller prospects.
Mine Owners/Operators and Mills
- Seven Troughs Mining Company (controlled Fairview and other ground).
- Seven Troughs Coalition Mining Company (operated Coalition properties and built the Coalition Cyanide Plant in 1911 to reprocess Kindergarten tailings).
- Kindergarten Mill operators (various lessees).
- Nevada State Gold Mines Company (later tunnel project).
Mills processed ore via stamp mills and cyanide:
- Kindergarten Mill (10-stamp; first in district, built winter 1907-1908 near Kindergarten vein).
- Coalition Cyanide Plant (built 1911 below Kindergarten Mill).
- Mazuma Hills Mill (10-stamp, operated ~1908-1911).
- Derby Mill (20-stamp in Mazuma).
- Later efforts included a 50-ton or 100-ton cyanide mill (~1930s in some accounts) and a 5-stamp mill remnant at Tunnel Camp (one of Nevada’s most complete preserved examples).
Production: Money Earned and Tonnage
The district was not a massive producer compared to Nevada giants like Goldfield or Tonopah but featured very high-grade ore. Total historic production (primarily 1907-1955, with most pre-1921) is estimated at around 158,468 ounces of gold and 995,876 ounces of silver, grading roughly 35.6 g/t gold and 223.9 g/t silver overall.
Cumulative value is commonly reported as about $2 million in gold (1908-1921 period; some sources extend to ~$2-2.3 million total precious metals). This equates to substantial returns given high per-ton values (e.g., ore at $600/ton or far higher in bonanzas). Tonnage specifics are less detailed but include roughly 1 million tons of combined mine and mill dumps remaining today. Individual high-grade shipments drove much of the value rather than bulk low-grade ore.
The Seven Troughs District exemplifies Nevada’s ephemeral boom camps—rich but short-lived, shaped by geology, floods, and economics—leaving behind ghost town remnants, mill foundations, and mine workings still visible in the remote desert landscape.